S-Acetyl-PEG3-alcohol is widely used in the pharmaceutical and biotechnology industries as a versatile building block for drug development and conjugation. Its primary application lies in the synthesis of prodrugs, where it serves as a protective group for hydroxyl functionalities, enhancing the stability and bioavailability of active pharmaceutical ingredients. The compound is also utilized in the creation of polyethylene glycol (PEG) derivatives, which are essential for improving the solubility, circulation time, and efficacy of therapeutic agents. Additionally, it plays a role in bioconjugation strategies, enabling the attachment of drugs, peptides, or proteins to PEG chains for targeted delivery and reduced immunogenicity. Its acetyl group offers ease of deprotection under mild conditions, making it a valuable tool in organic synthesis and drug design.